The Problem of Asphalt Waste
Asphalt is a major contributor to construction and demolition waste across Canada. This creates an opportunity as used asphalt can be used as aggregate or reprocessed into new asphalt. While some jurisdictions in Canada do allow for recycled asphalt in their roads, many limit the recycled content to low percentages.
Why Recycle Asphalt Pavement?
Used asphalt is a by-product in the field of asphalt road rehabilitation. Asphalt recycling is a common practice that has been in place for many years in countries such as the Netherlands, Belgium, Germany, Norway, Denmark, Japan, Brazil and the United States.
The use of some reclaimed asphalt in asphalt production is the norm for all asphalt manufacturers across Canada. However, increasing allowable RAP content is hindered by the perception that recycled asphalt is of poorer quality or isn’t as durable as asphalt made of virgin material.
Increasing RAP content in roads presents significant benefits such as:
- diverting waste material from landfills,
- reducing transportation-related greenhouse gas emissions from transfer of RAP to landfill,
- preserving natural resources at local quarries,
- meeting government sustainability and environmental targets,
- encouraging a circular economy in construction.
A greenhouse gas emissions study from a Lafarge site in Richmond in 2016 estimated that 1 tonne of carbon dioxide equivalents (CO2e) is reduced for every 10 tonnes of RAP that is used in asphalt each year. These greenhouse gas savings come from decreased emissions associated with transporting rubble to landfills, and from reduced material movement to asphalt plants.
For instance, if a 5,000-tonne municipal paving project approves the use of 40% RAP, a savings of approximately 200-tonnes of CO2 would be realized. These greenhouse gas savings are equivalent to the emissions of approximately 66 cars per year.